There's absolutely a point in arguing with us. We're not as rigid as other types (cough INFJs cough), even though we seem rigid. If you show us irrefutable evidence of something, you can convince us. We just won't want to admit that we were wrong, because we're prideful creatures...
An example of an ESTJ being convinced that something is true=
ESTJ: That's not true! What about ____ and _____? Everyone knows about THOSE.
xxxx: Well, actually, check out these statistics from (insert credible source here). Also, here's why your logic is wrong... ___________.
ESTJ: ... Huh. Okay.
The "huh. okay." is their way of saying "I'm convinced now. I'll register that as fact from now on, and argue your side if the argument comes up again."
It could also mean: "God damn it, you're right. I can't believe I just spent all that time arguing the wrong side! I'll make a dismissive statement so we can move on to a different topic and I can avoid my severe and acute embarrassment."
Speaking of that, check out posts 745-8:
http://www.typologycentral.com/forums/sj-guardhouse/17823-ask-estj-75.html#post1085727